package com.hmdp.utils;


import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {

    //开始时间戳
    private static final long BEGIN_TIMESTAMP =1716940800L;
    private static final int COUNT_BITS = 32;//序列号位数
    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix){
        //生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);//时间戳
        long timestamp = nowSecond-BEGIN_TIMESTAMP;
        //生成序列号
        //获取当前日期，精确到天
        //后续需要获取当月统计量只需要获取到MM即可，年则yyyy
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //哪怕新的一天空值也会自动创建出对应的，不会空指针
        long count = stringRedisTemplate.opsForValue()
                .increment("icr:"+keyPrefix+":"+date);
        //拼接
        //向左移32位或直接通过字段补充
        return timestamp << COUNT_BITS | count;//出来的是十进制
    }

//    public static void main(String[] args) {
//        LocalDateTime time = LocalDateTime.of(2024,5,29,0,0,0);
//        long second = time.toEpochSecond(ZoneOffset.UTC);//时区
//        System.out.println("second="+second);//时间戳
//    }

}
